Trial on the Impact of Indirect Calorimetry-Guided Nutritional Support on Patient-Centered Outcomes in Critically Ill Patients - The OPTICal Study (OPTICal)

A Randomized Controlled Trial on the Impact of Indirect Calorimetry-Guided Nutritional Support on Patient-Centered Outcomes in Critically Ill Patients - The OPTICal Study

This multicentric randomized controlled trial aims to evaluate whether indirect calorimetry (IC)-guided nutritional support improves patient-centered outcomes in critically ill adult patients compared to standard formula-based nutritional strategies. The study includes mechanically ventilated patients expected to remain in the ICU for more than 72 hours. The intervention group will receive nutritional targets based on measured resting energy expenditure using the QNRG+ device, with a gradual escalation of energy delivery following current ESPEN guidelines. The primary outcome is quality of life at 3 months post-ICU admission, assessed using the EQ-5D-5L. Secondary outcomes include functional recovery, muscle preservation, infection rates, and rehospitalization. This study is the first to assess the long-term impact of IC-guided nutrition on recovery and quality of life using a patient-centered approach.

Study Overview

• Status: Recruiting
• Conditions: Critical Illness; ICU
• Intervention / Treatment: Other: Indirect Calorimetry Group; Other: Control Group - Formula-Based Group

• Study Type: Interventional
• Enrollment (Estimated): 356
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Claudia Paula Heidegger, Prof.; Phone Number: +41223727440; Email: claudia.heidegger@hug.ch
• Study Contact Backup: Name: Aude de Watteville, MSc; Phone Number: +41795533998; Email: aude.dewatteville@hug.ch

Study Locations

• Switzerland
  • Geneva, Switzerland
    • Recruiting
    • Geneva University Hospital
    • Contact: Claudia Paula Heidegger, Prof.; Phone Number: +41223727440; Email: claudia.heidegger@hug.ch
    • Contact: Aude de Watteville, MSc; Phone Number: +41795533998; Email: aude.dewatteville@hug.ch
    • Principal Investigator: Claudia Heidegger, Prof.
    • Sub-Investigator: Aude de Watteville, MSc
    • Sub-Investigator: Hannah Wozniak, Dr. med
  • Nyon, Switzerland
    • Recruiting
    • GHOL
    • Contact: Mallory Moret, Dr. med.; Phone Number: +41 (0)22 994 67 47; Email: mallory.moretbochatay@ghol.ch
  • Zurich, Switzerland
    • Recruiting
    • Zürich University Hospitals
    • Contact: Mattia Müller, Dr. med.; Phone Number: 0794184324; Email: mattia.muller@usz.ch

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

All patients admitted to the ICU with the following criteria:

• ≥18 years old
• On Mechanical Ventilation
• Expected ICU length of stay >72 hours

Exclusion Criteria:

• Refusal of the family or patient
• Patient transferred from another ICU
• Pregnant patient
• Patient is planned for a withdrawal of care or is actively dying
• Cognitive disorder before ICU
• Patient is in jail
• Patients already enrolled in the ongoing NutriPhyT trial

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Intervention Group - Indirect Calorimetry Group	Other: Indirect Calorimetry Group; Nutritional targets measured by IC starting on Day 4; Repeated IC measurements 2 times weekly performed with the QNRG+ device; Gradual escalation to 80%-100% caloric coverage by Day 4
Active Comparator: Control Group - Formula-Based Group	Other: Control Group - Formula-Based Group; Nutritional targets determined using predictive equations (pragmatic, set at local level); Escalation as per local protocol

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Quality of life (EQ-5D-5L)	Measured using the EQ-5D-5L: 0-100	At 3 months after ICU admission

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mortality		Up to 3 months after ICU admission
Nosocomial infection	Defined as the initiation of a new antibiotic treatment lasting at least 72 hours, associated with a documented diagnosis of infection in the patient's chart	Up to 28 days after ICU admission
Pressure soar		Up to 28 days after ICU admission
Energy deficit in kcal	according to the energy target defined by IC or predictive formula depending on the randomization group	Up to 28 days after ICU admission
Protein deficit in grams	according to the protein target defined by predictive formula	Up to 28 days after ICU admission
Ventilation-free days		Measured at day 28 after ICU admission
ICU free-days		Measured at day 28 after ICU admission
Functional recovery: Bartel Index	Using Barthel Index: 0-100	At ICU discharge or up to 28 days after ICU admission and at 3 months after ICU discharge
Gerneral well-being: Edmonton Symptom Assessment Scale	Using Edmonton Symptom Assessment Scale (ESAS) : 0-90	At ICU discharge or up to 28 days after ICU admission and at 3 months after ICU discharge
Readmission and rehospitalization rates		Until 3-month post-ICU admission
Discharge place		Until 3 months after ICU admission
Return to work		Until 3 months after ICU admission
Disability and functioning: WHO Disability Assessment Schedule	Using WHO Disability Assessment Schedule (WHODAS 2.0): 0-48	At 3-month post ICU admission
Disability and functioning: Clinical Frailty Scale	Using Clinical Frailty Scale (CFS): 1-9	At 3-month post ICU admission
Disability and functioning: Short-form 12	Using Short-form 12 (SF-12): 0-100	At 3-month post ICU admission
Disability and functioning: MOCA-5	Using montreal cognitive assessment- 5 min (MOCA-5): 0-15	At 3-month post ICU admission
Disability and functioning: Patient Health Questionnaire-9	Using Patient Health Questionnaire-9 (PHQ-9): 0-27	At 3-month post ICU admission

Collaborators and Investigators

• Sponsor: HEIDEGGER CP
• Collaborators: University Hospital, Zürich; GHOL Nyon Hospital

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2026
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): September 1, 2027

Study Registration Dates

• First Submitted: August 7, 2025
• First Submitted That Met QC Criteria: January 6, 2026
• First Posted (Actual): January 15, 2026

Study Record Updates

• Last Update Posted (Actual): May 19, 2026
• Last Update Submitted That Met QC Criteria: May 15, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Nutrition; Nutrition therapy; Indirect calorimetry; Predictive formula
• Additional Relevant MeSH Terms: Pathologic Processes; Disease Attributes; Pathological Conditions, Signs and Symptoms; Critical Illness
• Other Study ID Numbers: OPTICal2025

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No